package carrierqueue

import (
	"context"
	stderrors "errors"
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/redis/go-redis/v9"

	"github.com/break/junhong_cmp_fiber/pkg/constants"
)

// StopResumeCommand 是写入停复机队列的一条指令。
type StopResumeCommand struct {
	CardID    uint
	CarrierID uint
	Action    string   // constants.StopResumeActionStop / StopResumeActionStart
	Reason    string   // 停机原因
	Scenes    []string // 触发场景
	Source    string   // 请求来源（日志与排查）
}

// CommandState 是卡当前停复机指令的解析结果。
type CommandState struct {
	Exists      bool
	Action      string
	Reason      string
	Scenes      []string
	Source      string
	CarrierID   uint
	Version     int64
	FailCount   int
	FirstFailed time.Time
	LastError   string
	Pending     bool
	Unknown     int
	WrittenAt   time.Time
	NextAt      time.Time // 队列中的可执行时间（零值表示不在队列中）
	LastCallAt  time.Time
}

// WriteCommand 写入或覆盖卡的停复机指令，返回新版本号。
func (s *Store) WriteCommand(ctx context.Context, cmd StopResumeCommand) (int64, error) {
	if cmd.CardID == 0 || cmd.CarrierID == 0 {
		return 0, stderrors.New("停复机指令缺少卡或运营商账户")
	}
	return srWriteScript.Run(ctx, s.redis,
		[]string{constants.RedisCardStopResumeCmdKey(cmd.CardID), constants.RedisCarrierStopResumeQueueKey(cmd.CarrierID),
			constants.RedisCardStopResumeClaimKey(cmd.CardID)},
		cmd.Action, cmd.Reason, constants.JoinStopResumeScenes(cmd.Scenes), cmd.Source, cmd.CarrierID, time.Now().UnixMilli(), cmd.CardID,
	).Int64()
}

// SRClaimInput 是一次账户停复机领取的参数。
type SRClaimInput struct {
	CarrierID     uint
	Lease         time.Duration
	InflightLimit int // 账户停复机执行上限（含执行中）
	Budget        int // 停复机所在限流组本秒剩余；-1 表示不按 QPS 限制
	TokenPrefix   string
	MinInterval   time.Duration
}

// SRClaimed 是一条被领取的停复机指令。
type SRClaimed struct {
	CardID  uint
	Token   string
	Version int64
	Action  string
	Pending bool
}

// ClaimStopResume 领取账户到期停复机指令，返回领取结果与本轮清理的过期执行数。
func (s *Store) ClaimStopResume(ctx context.Context, input SRClaimInput) ([]SRClaimed, int64, error) {
	raw, err := srClaimScript.Run(ctx, s.redis,
		[]string{constants.RedisCarrierStopResumeQueueKey(input.CarrierID), constants.RedisCarrierStopResumeRunningKey(input.CarrierID)},
		time.Now().UnixMilli(), input.Lease.Milliseconds(), input.InflightLimit, input.TokenPrefix, input.MinInterval.Milliseconds(), input.Budget,
	).Slice()
	if err != nil || len(raw) == 0 {
		return nil, 0, err
	}
	expired, _ := raw[0].(int64)
	claimed := make([]SRClaimed, 0, (len(raw)-1)/5)
	for index := 1; index+4 < len(raw); index += 5 {
		cardID, _ := strconv.ParseUint(fmt.Sprint(raw[index]), 10, 64)
		version, _ := strconv.ParseInt(fmt.Sprint(raw[index+2]), 10, 64)
		claimed = append(claimed, SRClaimed{CardID: uint(cardID), Token: fmt.Sprint(raw[index+1]), Version: version,
			Action: fmt.Sprint(raw[index+3]), Pending: fmt.Sprint(raw[index+4]) == "1"})
	}
	return claimed, expired, nil
}

// AcquireStopResumeExec 抢停复机指令执行权：1 抢到，0 处理中标记已不是该 token，-1 已有执行者。
func (s *Store) AcquireStopResumeExec(ctx context.Context, cardID uint, token, execValue string, ttl time.Duration) (int64, error) {
	return acquireExecScript.Run(ctx, s.redis, []string{constants.RedisCardStopResumeClaimKey(cardID), constants.RedisCardStopResumeExecKey(cardID)},
		token, execValue, ttl.Milliseconds()).Int64()
}

// SRFinish 是一次停复机指令收尾。
type SRFinish struct {
	CardID    uint
	CarrierID uint
	Token     string
	Version   int64
	Done      bool // true 结束并删除指令
	Unknown   bool // 本次结果未知：版本已变大时把待确认带到新指令
	NextAt    time.Time
	Set       map[string]string
	Del       []string
}

// FinishStopResume 停复机指令收尾：返回 0 token 不一致、1 正常、2 版本已变大保留新指令。
func (s *Store) FinishStopResume(ctx context.Context, finish SRFinish) (int64, error) {
	done := "0"
	if finish.Done {
		done = "1"
	}
	now := time.Now()
	next := finish.NextAt
	if next.IsZero() || next.Before(now) {
		next = now
	}
	unknown := "0"
	if finish.Unknown {
		unknown = "1"
	}
	args := []any{finish.Token, finish.CardID, finish.Version, done, next.UnixMilli(), now.UnixMilli(), unknown, len(finish.Set)}
	for field, value := range finish.Set {
		args = append(args, field, value)
	}
	for _, field := range finish.Del {
		args = append(args, field)
	}
	return srFinishScript.Run(ctx, s.redis,
		[]string{constants.RedisCardStopResumeCmdKey(finish.CardID), constants.RedisCardStopResumeClaimKey(finish.CardID),
			constants.RedisCardStopResumeExecKey(finish.CardID), constants.RedisCarrierStopResumeRunningKey(finish.CarrierID),
			constants.RedisCarrierStopResumeQueueKey(finish.CarrierID)},
		args...).Int64()
}

// ReleaseStopResume 发布失败时释放停复机指令处理中标记并恢复为立即可领取。
func (s *Store) ReleaseStopResume(ctx context.Context, cardID, carrierID uint, token string) error {
	return srReleaseScript.Run(ctx, s.redis,
		[]string{constants.RedisCardStopResumeClaimKey(cardID), constants.RedisCarrierStopResumeRunningKey(carrierID),
			constants.RedisCarrierStopResumeQueueKey(carrierID)},
		token, cardID, time.Now().UnixMilli()).Err()
}

// MarkStopResumeCall 记录本卡一次停复机网关调用（停机与复机合计），供单卡最小重试间隔判断。
func (s *Store) MarkStopResumeCall(ctx context.Context, cardID uint, at time.Time, keep time.Duration) error {
	if keep < time.Hour {
		keep = time.Hour
	}
	return s.redis.Set(ctx, constants.RedisCardStopResumeLastCallKey(cardID), at.UnixMilli(), keep).Err()
}

// LastStopResumeCall 返回本卡最近一次停复机网关调用时间；没有记录返回零值。
func (s *Store) LastStopResumeCall(ctx context.Context, cardID uint) (time.Time, error) {
	ms, err := s.redis.Get(ctx, constants.RedisCardStopResumeLastCallKey(cardID)).Int64()
	if stderrors.Is(err, redis.Nil) {
		return time.Time{}, nil
	}
	if err != nil {
		return time.Time{}, err
	}
	return time.UnixMilli(ms), nil
}

// ReadCommand 读取卡当前停复机指令与队列位置。
func (s *Store) ReadCommand(ctx context.Context, cardID uint) (CommandState, error) {
	raw, err := s.redis.HGetAll(ctx, constants.RedisCardStopResumeCmdKey(cardID)).Result()
	if err != nil {
		return CommandState{}, err
	}
	state := ParseCommand(raw)
	if last, lastErr := s.LastStopResumeCall(ctx, cardID); lastErr == nil {
		state.LastCallAt = last
	}
	if state.Exists && state.CarrierID > 0 {
		member := strconv.FormatUint(uint64(cardID), 10)
		if score, scoreErr := s.redis.ZScore(ctx, constants.RedisCarrierStopResumeQueueKey(state.CarrierID), member).Result(); scoreErr == nil {
			state.NextAt = time.UnixMilli(int64(score))
		}
	}
	return state, nil
}

// ParseCommand 解析停复机指令 Hash。
func ParseCommand(raw map[string]string) CommandState {
	state := CommandState{Exists: raw[srFieldAction] != ""}
	state.Action, state.Reason, state.Source, state.LastError = raw[srFieldAction], raw[srFieldReason], raw[srFieldSource], raw[srFieldError]
	state.Scenes = constants.SplitStopResumeScenes(raw[srFieldScenes])
	if value, err := strconv.ParseUint(raw[srFieldCarrier], 10, 64); err == nil {
		state.CarrierID = uint(value)
	}
	state.Version, _ = strconv.ParseInt(raw[srFieldVersion], 10, 64)
	state.FailCount, _ = strconv.Atoi(raw[srFieldFail])
	state.Unknown, _ = strconv.Atoi(raw[srFieldUnknown])
	state.Pending = raw[srFieldPending] == "1"
	if ms, err := strconv.ParseInt(raw[srFieldFirst], 10, 64); err == nil && ms > 0 {
		state.FirstFailed = time.UnixMilli(ms)
	}
	if ms, err := strconv.ParseInt(raw[srFieldAt], 10, 64); err == nil && ms > 0 {
		state.WrittenAt = time.UnixMilli(ms)
	}
	return state
}

// 停复机指令字段名导出给执行器组装收尾写入。
const (
	SRFieldFail    = srFieldFail
	SRFieldFirst   = srFieldFirst
	SRFieldError   = srFieldError
	SRFieldPending = srFieldPending
	SRFieldUnknown = srFieldUnknown
)

// RequestDeviceEval 请求一次设备维度判断：递增版本、合并场景、设备进入判断队列。
func (s *Store) RequestDeviceEval(ctx context.Context, deviceID uint, scenes []string) error {
	if deviceID == 0 {
		return stderrors.New("设备判断缺少设备")
	}
	args := []any{deviceID, time.Now().UnixMilli()}
	for _, scene := range constants.SplitStopResumeScenes(constants.JoinStopResumeScenes(scenes)) {
		args = append(args, scene)
	}
	return deviceRequestScript.Run(ctx, s.redis,
		[]string{constants.RedisDeviceEvalVersionKey(deviceID), constants.RedisDeviceEvalScenesKey(deviceID), constants.RedisDeviceEvalQueueKey,
			constants.RedisDeviceEvalClaimKey(deviceID)},
		args...).Err()
}

// DeviceEvalClaimed 是一次被领取的设备判断。
type DeviceEvalClaimed struct {
	DeviceID uint
	Token    string
	Version  string
	Scenes   []string
}

// ClaimDeviceEvals 领取到期设备判断。
func (s *Store) ClaimDeviceEvals(ctx context.Context, lease time.Duration, limit int, tokenPrefix string) ([]DeviceEvalClaimed, int64, error) {
	raw, err := deviceClaimScript.Run(ctx, s.redis, []string{constants.RedisDeviceEvalQueueKey, constants.RedisDeviceEvalRunningKey},
		time.Now().UnixMilli(), lease.Milliseconds(), limit, tokenPrefix).Slice()
	if err != nil || len(raw) == 0 {
		return nil, 0, err
	}
	expired, _ := raw[0].(int64)
	claimed := make([]DeviceEvalClaimed, 0, (len(raw)-1)/4)
	for index := 1; index+3 < len(raw); index += 4 {
		deviceID, _ := strconv.ParseUint(fmt.Sprint(raw[index]), 10, 64)
		claimed = append(claimed, DeviceEvalClaimed{DeviceID: uint(deviceID), Token: fmt.Sprint(raw[index+1]),
			Version: fmt.Sprint(raw[index+2]), Scenes: constants.SplitStopResumeScenes(fmt.Sprint(raw[index+3]))})
	}
	return claimed, expired, nil
}

// AcquireDeviceEvalLock 抢设备判断锁（执行权）：1 抢到，0 处理中标记已不是该 token，-1 已有判断在执行。
func (s *Store) AcquireDeviceEvalLock(ctx context.Context, deviceID uint, token, value string, ttl time.Duration) (int64, error) {
	return acquireExecScript.Run(ctx, s.redis, []string{constants.RedisDeviceEvalClaimKey(deviceID), constants.RedisDeviceEvalLockKey(deviceID)},
		token, value, ttl.Milliseconds()).Int64()
}

// FinishDeviceEval 设备判断收尾：返回 0 token 不一致、1 完成、2 版本变大已重新排队、3 已推后。
func (s *Store) FinishDeviceEval(ctx context.Context, claimed DeviceEvalClaimed, deferFor time.Duration) (int64, error) {
	args := []any{claimed.Token, claimed.DeviceID, claimed.Version, time.Now().UnixMilli(), deferFor.Milliseconds()}
	for _, scene := range claimed.Scenes {
		args = append(args, scene)
	}
	return deviceFinishScript.Run(ctx, s.redis,
		[]string{constants.RedisDeviceEvalClaimKey(claimed.DeviceID), constants.RedisDeviceEvalLockKey(claimed.DeviceID),
			constants.RedisDeviceEvalRunningKey, constants.RedisDeviceEvalVersionKey(claimed.DeviceID),
			constants.RedisDeviceEvalScenesKey(claimed.DeviceID), constants.RedisDeviceEvalQueueKey},
		args...).Int64()
}

// ReleaseDeviceEval 发布失败时释放设备判断处理中标记。
func (s *Store) ReleaseDeviceEval(ctx context.Context, deviceID uint, token string) error {
	return srReleaseScript.Run(ctx, s.redis,
		[]string{constants.RedisDeviceEvalClaimKey(deviceID), constants.RedisDeviceEvalRunningKey, constants.RedisDeviceEvalQueueKey},
		token, deviceID, time.Now().UnixMilli()).Err()
}

// StopResumeQueueStats 是账户停复机队列的即时统计。
type StopResumeQueueStats struct {
	Queued  int64
	Due     int64
	Running int64
	Pending int64
}

// StopResumeStats 读取账户停复机队列长度、到期数与执行中数；待确认数按队列成员抽样统计（最多 500 个）。
func (s *Store) StopResumeStats(ctx context.Context, carrierID uint) (StopResumeQueueStats, error) {
	now := strconv.FormatInt(time.Now().UnixMilli(), 10)
	queueKey := constants.RedisCarrierStopResumeQueueKey(carrierID)
	pipe := s.redis.Pipeline()
	queued := pipe.ZCard(ctx, queueKey)
	due := pipe.ZCount(ctx, queueKey, "-inf", now)
	running := pipe.ZCount(ctx, constants.RedisCarrierStopResumeRunningKey(carrierID), now, "+inf")
	members := pipe.ZRange(ctx, queueKey, 0, 499)
	if _, err := pipe.Exec(ctx); err != nil && !stderrors.Is(err, redis.Nil) {
		return StopResumeQueueStats{}, err
	}
	stats := StopResumeQueueStats{Queued: queued.Val(), Due: due.Val(), Running: running.Val()}
	if ids := members.Val(); len(ids) > 0 {
		check := s.redis.Pipeline()
		results := make([]*redis.StringCmd, 0, len(ids))
		for _, id := range ids {
			cardID, convErr := strconv.ParseUint(strings.TrimSpace(id), 10, 64)
			if convErr != nil {
				continue
			}
			results = append(results, check.HGet(ctx, constants.RedisCardStopResumeCmdKey(uint(cardID)), srFieldPending))
		}
		_, _ = check.Exec(ctx)
		for _, result := range results {
			if result.Val() == "1" {
				stats.Pending++
			}
		}
	}
	return stats, nil
}

// IncrStopResumeStat 累加账户停复机执行计数（10 分钟分桶，保留 2 小时）。
func (s *Store) IncrStopResumeStat(ctx context.Context, carrierID uint, field string) {
	key := constants.RedisCarrierStopResumeStatKey(carrierID, time.Now().Unix()/constants.StopResumeStatBucketSeconds)
	pipe := s.redis.Pipeline()
	pipe.HIncrBy(ctx, key, field, 1)
	pipe.Expire(ctx, key, 2*time.Hour)
	_, _ = pipe.Exec(ctx)
}

// StopResumeStatLastHour 汇总账户近 1 小时（最近 6 个分桶）的停复机执行计数。
func (s *Store) StopResumeStatLastHour(ctx context.Context, carrierID uint) map[string]int64 {
	current := time.Now().Unix() / constants.StopResumeStatBucketSeconds
	pipe := s.redis.Pipeline()
	cmds := make([]*redis.MapStringStringCmd, 0, 6)
	for bucket := current - 5; bucket <= current; bucket++ {
		cmds = append(cmds, pipe.HGetAll(ctx, constants.RedisCarrierStopResumeStatKey(carrierID, bucket)))
	}
	_, _ = pipe.Exec(ctx)
	totals := map[string]int64{}
	for _, cmd := range cmds {
		for field, value := range cmd.Val() {
			count, _ := strconv.ParseInt(value, 10, 64)
			totals[field] += count
		}
	}
	return totals
}